Apparatus for processing electrostatic images

ABSTRACT

An apparatus for processing the latent image which is produced when electrophotographic film is exposed, the latent image being formed on the photoconductive surface of the said film. A capsule having toner particles suspended in a toner liquid is provided, having a spongelike member on its interior to retain the suspension, a relatively rigid foraminous wall and other walls which are flexible. The foraminous wall is brought into juxtaposition to the photoconductive surface of the electrophotographic film, one or more flexible walls are pressed to collapse the capsule and the toner suspension is squeezed out of the perforations in the foraminous wall so that the entire photoconductive surface is subjected to the toner simultaneously. The said surface is flooded and the suspension confined thereon by suitable blocking means. The interior spongelike member will suck the remaining suspension back into the interior of the capsule when the flexible walls are released, the construction being such as to provide for such resilience, leaving only the toner which has adhered to and rendered visible the latent image. Thereafter the capsule may be discarded to be replaced by a fresh one for the next processing but may be left in place if there is sufficient toner to process other films. The film may thereafter be subjected to toner fusing radiation to cause the adhering toner to fuse to the surface of the film. The foraminous wall is spaced from and parallel with the surface of the film during the collapse of the flexible walls of the capsule so that the streams of suspension emerging from the perforations are directed normal to the said photoconductive surface. In addition, the exterior surface of the wall is coated with a conductive layer and biased to a d.c. potential of polarity the same as the surface charge of the toner particles electrostatically to drive the particles out of the perforations and directly to the photoconductive surface, eliminating uneven toner deposit.

United States Patent Kuehnle 1 1 Apr. 22, 1975 1 1 APPARATUS FORPROCESSING ELECTROSTATIC IMAGES Bedford. Mass.

[22] Filed: Jan. 12, 1973 [21] Appl. No.: 323,108

[52] US. Cl. 118/637; 117/37 LE; l18/DIG. 23 [51] Int. Cl G03g 13/00[58] Field of Search 96/1 LY; 117/37 LE;

118/264. 265, 401. 637. DIG. 23. 266

[56] References Cited UNITED STATES PATENTS 2.987.955 6/1961 Sasscnberg118/264 3.096.198 7/1963 Schaffcrt 118/637 3.133.484 5/1964 Wright118/637 3.343.956 9/1967 Wright 118/637 3.472.676 10/1969 Cassicrs cta1. 118/637 3.696.782 10/1972 McConnell 118/637 3.753.706 8/1973 Sankuset a1. 96/1 LY 3.776.630 12/1973 Ohno ct a1. 118/637 X 3.795.351 3/1974Lchmann 222/209 Primary Examiner-Mervin Stein Assistant E.raminerLeoMillstein Attorney. Agent. or FirmSilverman & Cass [57] ABSTRACT Acapsule having toner particles suspended in a toner liquid is provided.having a spongelike member on its interior to retain the suspension, arelatively rigid foraminous wall and other walls which are flexible. Theforaminous wall is brought into juxtaposition to the photoconductivesurface of the electrophotographic film. one or more flexible walls arepressed to collapse the capsule and the toner suspension is squeezed outof the perforations in the foraminous wall so that the entirephotoconductive surface is subjected to the toner simultaneously. Thesaid surface is flooded and the suspension confined thereon by suitableblocking means.

The interior spongelike member will suck the remaining suspension backinto the interior of the capsule when the flexible walls are released.the construction being such as to provide for such resilience, leavingonly the toner which has adhered to and rendered visible the latentimage. Thereafter the capsule may be discarded to be replaced by a freshone for the next processing but may be left in place if there issufficient toner to process other films. The film may thereafter besubjected to toner fusing radiation to cause the adhering toner to fuseto the surface of the film.

The foraminous wall is spaced from and parallel with the surface of thefilm during the collapse of the flexible walls of the capsule so thatthe streams of suspension emerging from the perforations are directednormal to the said photoconductive surface. In addition, the exteriorsurface of the wall is coated with a conductive layer and biased to ad.c. potential of polarity the same as the surface charge of the tonerparticles electrostatically to drive the particles out of theperforations and directly to the photoconductive surface, eliminatinguneven toner deposit.

14 Claims, 6 Drawing Figures PATENTEDAPRZZIBYS SHEET 1 0F 2 FIG.

C +50 VOLTS DC. 20 22 APPARATUS FOR PROCESSING ELECTROSTATIC IMAGESCROSS-REFERENCE TO RELATED APPLICATIONS Reference is made herein to acopending Pat. application Ser. No. 260,848, filed June 8, 1972 andentitled BACKGROUND OF THE INVENTION This invention relates generally tothe processing of electrostatic images and more particularly isconcerned with applying toner particles to such images.

In the field of xerographic or electrostatic image recording, a latentimage is formed on a plate or other member. This latent image is thepattern which is projected onto the member by a lens system or the like.Prior to the projection, the member is charged by corona therebyproviding a large number of electrons at or near the photoconductivesurface which are capable of migrating when struck by photons. Theprojection or exposure as it may be termed, causes electrons to leavethe surface, in proportion to the amount of impinging light at anyincrement of the surface. The latent image is thus formed of electronsand the absence of electrons.

The charge originally placed on the photoconductive surface will decayin time and with it the latent image will fade. The image is madevisible, according to the art, by the application of toner particlesthereto, these particles having electrostatic charges which cause themto adhere the electrons on the photoconductive surface of the member. Inthis manner the image is formed on the member. Toner particles areminute particles of carbon, resins and the like.

In most xerographic equipment, the member to which the particles adherecomprises a selenium drum and the drum is pressed against a sheet ofpaper to transfer the image to the paper. Then the paper surfacecarrying the toner particles is rapdidly heated causing the particels tofuse permanently to the paper. In other apparatus the latent image isformed directly on the sheet of paper which has been coated wtih a zincoxideresin mixture that is photoconductive. This process is known aselectrofax, and the toner is applied in liquid form, the liquid normallybeing a hydrocarbon within which the toner particles will acheivesurface charge. The xerographic process using a drum utlilizes a type oftoning known as cascade toning in which the toner particles are mixedwith plastic beads and applied in this dry mixture form. Only the tonerparticles adhere to the selenium surface of the drum, this being thephotoconductive surface.

The invention was developed for use with electrostatic image apparatusof a nature that differs from those mentioned above, primarily in thatthe construction of the member carrying the latent image is different,giving rise to many advantages. Principally, the speed of thephotoconductive surface is so great and its sensitivity so high that themember can be used much in the same manner as the ordinary photographiccameras, but without many of the disadvantages thereof. The memberitself comprisies a structure that can be called an electrophotographicfilm, comprising a substrate of polyester or the like carrying an ohmiclayer bonded thereto and an inorganic photoconductive coating bonded tothe surface of the ohmic layer. Reference may be made to the copendingpatent applications for detailed descriptions of saidelectrophotographic film.

This electrophotographic film has a very high dark decay characteristicand a large differential between dark and light decay characteristics.Its photoconductive surface can be charged very quickly in a matter of afraction of a second and exposed at rates comparable with those used toexpose high speed silver halide emulsion photographic films. The primarymanner of use of the electrophotographic film of said copendingapplications is to produce transparencies, since the combination of theohmic layer and the photoconductive coating on the clear plasticsubstrate will provide an extremely thin lamination which is transparentto a substantial degree between about percent and percent. Accordingly,in forming the visible image, it is desired to apply toner to thephotoconductive surface and thereafter to fuse the toner particlesdirectly to the lamination itself.

Due to these desires and the characteristics of the electrophotographicfilm, it is essential that the toning of the member be done as rapidlyas possible after exposure has occurred. This, of course, is to preventthe decay of the latent image along with the decay of the charge on thephotoconductive member. The apparatus and method of the invention weredesigned for and are especially adapted for such utilization, but arenot so limited. The teachings of the invention are applicable in othertechniques and with other apparatus as well.

Aside from the requirements of the high speed electrophotographic filmwhich has been mentioned above, all of which are met by the invention,many disadvantages of prior methods and apparatus for toning have beenobviated. These disadvantages which are mentioned hereinafter are causedby the nature of the xerographic or electrofax process to some extent,but the methods and apparatus for toning are a considerable factor aswell.

Where baths are used, as in electrofax, the images which are producedare inherently nonuniform because the sheet of paper carrying thephotoconductive surface is immersed into the bath from one edge andpasses progressively through to the other. The decay of the image andsurface charge is still going on while this occurs so that there isbound to be fading from the leading to the trailing edge. In the case ofthe high speed electrophotographic film of the copending applicationsthe fading would be aggravated in a bath-type of toning process. Theapparatus and method of the invention provide for application of thetoner suspension simultaneously over the entire photoconductive surfaceof the elcctrophotographic film.

Another problem with prior methods and apparatus is fidelity or tone, inthe popular sense, of the resulting image. Where an exposure is properwith respect to a given set of conditions, some time later, after thebath of toner in liquid has been used for a while, the toner becomesdepleted. The concentration of toner particles changes and the imageresulting losses contrast and depth.

As will be understood from the description of the in vention the methodand apparatus call for the toner suspension to be accurately andprecisely prepared in advance, encapsulated in a suitable enclosure,used in one instance and the remainder discarded. In this way, totaluniformity is achieved every time. Exposure can always be preciselyrelated to the toner concentration by the manufacture and can be reliedupon to obtain optimum results for each use. If desired, without anychanges whatsoever, the enclosure may be used several times prior todiscarding.

In prior apparatus toner application has produced bad grey scales andnonuniform black areas. The xero graphic equipment in use at the presenttime cannot produce images with large uniform dark areas. This is knownas edge effect. Such areas come out light in the center and dark alongthe edges, this being caused by the tendency of the toner particles toseek the maximum field differential thereby migrating to the edges ofthe images. According to the invention, this is obviated by a novelbiasing method and apparatus which will be described, the resultingimages being uniform in color and having excellent grey scalecharacteristics.

Electrostatic image producing apparatus which utilize dry tonerapplicaiton in the process of the photoconductive surfaces of themembers used have prob lems of uniformity, waste, and difficulties inhandling. There are mixtures of plastic beads and iron filings whichhave to be handled, separated, and the foregoing particles andsurplussage discarded. Often, where dry foreign particles are includedin the mixtures, the application of toner is inefficient because ofadherence to the foreign particles. Other structures use magneticbrushes to provide the necessary surface chage to the toner particles,this being more apparatus to handle the keep clean.

Given the necssity of building a small hand-held camera type of devicefor producing the electrostatic record, prior methods of processingrequire apparatus which is complex, bulky and expensive. It is unlikelythat such a device could be manufactured with te known technologyrepresented by such prior methods and apparatus. The invention herein,on the other hand, makes such a project feasible and practical.

In electrostaic image producing apparatus known, the fields representedby the latent images on the photoconductive surfaces are relativelyweak. Furthermore, their strength decreases with distance from thesurface by exponential factors so that the attraction for tonerparticles is not very great. Accordingly, such apparatus depends in someinstances importantly on gravity to bring the particles within thestronger portions of teh fields close to the surfaces comprising thephotoresponsive layers, and in other instances the toner is mechnicallyagitated too throw the particles into such fields. Two adverse resultsare nonuniformity and time loss. Surfaces which are not horizontallydisposed with the toner applied on the upper side suffer to some greaterextent from these two problems.

The bias used in accordance with the invention drives the particlesdirectly at the photoconductive surface an thus obviates theabove-described disadvantages. Specifically, besides uniformity, theprocessing or timing is accomplished substantially instantaneously andirre spective of the disposition of the photoconductive surface.

A large measure of difficulty with prior apparatus is additionallyeliminated by providing disposable capsules of toner which areeconomical and easy to use, besides giving uniform results.

Many advantages which are not specifically described above are inherentin the invention and these will become apparent from the descriptionwhich follows.

SUMMARY OF THE INVENTION The invention herein is characterized by theprovi sion of a capsule having a relatively rigid foraminous wall andother flexible walls, and interior spongelike member and the interiorbeing filled with toner suspended in a toner liquid. The combination ofwalls and spongelike member are constructed so that the capsule iscapable of being compressed or squeezed or collapsed and thereafter willrecover. The foraminous wall has an exterior conductive coating adaptedto be connected to a dc. potential source of polarity the same thesurface charge of the toner particles.

The capsule is used by bringing the exterior of the foraminous wall intoparallel and spaced juxtaposition to the photoconductive surface of anelectrophotographic film, the capsule and film framing member beingengaged to provide a confining chamber. The capsule is then squeezed sothat the toner suspension is pressed out of the perforations of theforaminous wall simulta neously over the entire photoconductive surfaceand confined within said chamber. When the capsule is released, itreturns to its original configuration and sucks the remaining liquid andtoner back into the capsule which may then be discarded. The latentimage has toner particles now adhered thereto and these may be fused tothe film when desired.

The bias serves to drive the toner particles in suspension directly fromthe perforations and against the photoconductive surface normal theretothereby eliminating edge effect.

Apparatus for using the capsule includes means for squeezing the sameand releasing the same while it is in engagement with the film.

The images resulting from the use of the capsule are clean, uniform,with excellent grey scales and with large dark areas havng continuoustonal range.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a fragmentary sectional viewtaken through the processing apparatus of the invention showing themanner in which toner suspension is applied to the pho toconductivesurface of an electrophotographic film:

FIG. 2 is a schematic view illustrating the manner in which theapparatus is associated with an electrostatic image producing device,showing additional details of the apparatus and related components:

Flg. 3 is a perspective view of a capsule of toner constructed inaccordance with the invention, showing the manner in which a pressuresensitive storage member is removed from the capsule to enable thecapsule to be used immediately;

FIG. 4 is a fragmentary sectional view taken through the capsule of FIG.3, here shown in position for use but before use;

FIG. 5 is a view similar to that of FIG. 4 but showing the manner inwhich the capsule is used by expressing suspension from the same; and

FIG. 6 is a view similar to that of FIGS. 4 and 5 but showing the mannerin which the suspension has been sucked back into the capsule leavingtoner particles adhered to the electrophotographic film.

DESCRIPTION OF PREFERRED EMBODIMENTS Generally the invention hereinenables practically instantaneous processing, that is, applicaiton oftoner to electrophotographic film. This is advantageous generally forapparatus which produce electrostatic images and particularly inadvantageous when used with the type of electrophotographic film that isdisclosed in the copending applications mentioned hereinabove.

According to the invention, the toner particles in a liquid susupensionare carried in a capsule which may be sealed by a suitable removablemember for storage purposes. When ready for use the removable member ispeeled from a foraminous surface and the capsule positioned adjacent theexposed photoconductive surface of the electrophotographic film, Thejuxtaposed articles having engaging surfaces forming an enclosedchamber. The capsule is squeezed, driving the toner directly to thephotoconductive surface over its entire area simultaneously. An electricbias enhances the movement of toner particles to all areassimultaneously.

After the toner has adhered to the latent image the capsule is releasedand the remaining suspension is sucked back into the capsule which maybe re-used several more times or discarded. The moist image quicklydries, and if satisfactory, may be fused to the film by the operator.

FIG. I illustrates a fragmentary section through a capsule shown in Juxtaposition to an electrophotographic film in an exaggerateddimensional form. The capsule itself is shown completely in FIGS. 2 and3. Reference may first be had to these three figures for the initialexplanation.

The capsule 10 of the invention of the invention comprises a planarrectangular wall 12 which is described herein as foraminous. It isprovided with a large number of tiny perforations or passageways 14which pass thorugh the wall 12 transversely thereof, from the innersurface 16 to the outer surface of the wall which is designated 18. Thesaid outer surface 18 is coated with a thin coating or layer 20 ofconductive materials such as aluminum. The wall 12 may be formed ofrigid polyvinyl chloride or other relatively rigid insulating materialthat has the necessary characteristics. A thickness of about onemilimeter will be sufficient. The wall 12 is required to be ofinsulating material, capable of being perforated to produce very finepores say of the order of 50 microns in diameter. It should beimpervious to the chemicals which are used. In the present structure,the toner suspension which is used is a liquid hydrocarbon comprising aturnpentinelike substance known as isopar. Due to the nature of theinvention, since, as will be seen, the suspension is always encapsulateduntil it is used, the liquid used to suspend the toner particles can befreon or other much more volatile fluids.

The perforations 14 continue through the metallic coating 20. Thiscoating is quite thin compared with the wall 12 and in use is connectedto a potential source by a suitable conductor 22. As shown in FIG. 1,the potential is positive 50 volts do it being assumed that the surfacecharge on the toner particles in the capsule will also be positive. Thiswill be explained below.

Above the wall 12 as shown in FIG. 1 there is provided a rectangularmass of some resilient absorbent material, such as for example any ofthe man made commonly available sponges on the market today. This massis shown at 26 and may be in the form of an integral member or agranular mass. The only requirements of the mass 26 are that it beresilient to enable its recovery when squeezed and released; that ithave good capillary qualities to hold and release the toner suspension;and that it be chemically impervious to the toner liquid.

The remaining walls 28 of the capsule 10 are formed of a thin flexibleskin, for example molded or vacuumformed polyvinyl chloride, imperviousto the liquid used to suspend the toner particles. The walls will havean outwardly extending border 30 which is heat-sealed or otherwisewelded to the surface 16 around its periphery. The wall 12 convenientlycan be perforated all over so that the sealing of the enclosing walls 28thereto will block off a framing portion 32 surrounding the centralperforated portion 34. Obviously, the member forming the wall 12 couldbe stamped out of a larger perforated sheet or could be formed from asheet member that has only the center section 34 perforated. In anyevent, the capsule 10 has the framing border 32 surrounding the centralperforated area 34 and extending laterally outward of the rectangularbody enclosed by the walls 28.

As stated above, the sponge member or mass 26 has toner particles in aliquid suspension saturating the same. The perforated area 34 ispreferably closed off against entry of air or loss of suspension bymeans of a removable member 36 of paper or the like having a tab 388 forgrasping the member 36. This member may be of paper adhered withpressure sensitive adhesive that is not soluble in the liquid used tomake the suspension of toner. Actually, the perforations 14 are so smallthat it is not likely that much liquid will come through the same andcontact the adhesive which is shown at 40. This arrangement enables thecapsule to be stored and handled without loss of toner suspensions andprovides a surface for carrying printed instructions, expiration time,etc.

As pointed out, the outer surface of the wall 12 is coated with a verythin layer 20 of aluminum or the like metal to enable a bias tobe-applied to this layer. The capsule 10 may have a contact tab orextension 41 connected to the metal layer 20 to enable the bias to beapplied when the capsule is in position for use. This will be explainedin connection with FIG. 2. Instead of this arrangement, contact meansmay be provided for contacting any other part of the surface 20 when thecapsule is in position.

The capsule 10 is used by inserting the same into the electrostaticimage producing apparatus in juxtaposition to the member carrying thelatent image. FIG. 2 shows one such arrangement and also illustratessome of the other components of a device for recording images. Thiscould be stationary apparatus, a hand-held cameralike device, etc.

At the bottom of the view there is illusutrated a recording member 42which comprises a central rectangular transparent portion 44 and aframing border 46. The border 46 may be made of any suitable materialsuch as for example molded plastic and the transparent portion comprisesthe electrophotographic film such as for example, the type of articlewhich is disclosed in the copending applications. As understood fromtheh said copending applications, there is a photoconductive coating 48of an inorganic phtocondcutive compound, an ohmic or conductive layer50, also inorganic and a substrate member 52 of an insulating plasticsuch as an organic polymer. The total thickness of the two inorganiclayers 48 and 50 is less than 5,000 Angstroms and the substrate memberis of the order of fraction of a millimeter in thickness. Since themember 42 will be used as a transparency, the framing border 46 ispreferably slightly thicker than the entire film 44 so that said film isslightly spaced inwardly of the framing border front and back. Thus, ifthe perforated section 34 of the capsule is placed flush against thesurface of the member 42 and aligned with the film 44, the framingborder 32 will be pressed against and congruent with the framing border46 and the photoconductive coating 48 will have its surface spaced fromthe surface 34 by about 0.5 millimeter, depending upon the thickness ofthe framing border 46.

Preferably the electrophotographic film 44 is molded into the framingborder 46 of the member 42 so that the thickness is accuratelycontrolled. The ohmic layer 50 is required to be grounded when thesurface is charged and exposed. Thus there may be an internal conductor50 along one edge of the film 44 in connected with an external contact52 provided adjacent a lateral edge of the member 42 as shown.

When the capsule wall 12 and the member 42 are pressed into engagementwith one another, the space between the surface 34 and the surface ofthe photoconductive coating 48 forms a closed rectangular chamber 54which is dammed or closed off, at least insofar as liquid flow isconcerned, by the inner edges 56 of the framing border 46. This chamber54 is filled with toner suspension during the processing of the film 44.

In FIG. 2, the member 42 is shown mounted in a vertically movablecarrier 60 which is grounded in the electrostatic recording apparatusdesignated generally 62. The frames and housings and considerableauxiliary apparatus and components are not shown here since they are notessential to the explanation. The contact 52 of the member 42 engagesthe carrier to ground the ohmic layer 50 of the film 44.

An optical system including lenses and the like is symbolicallyindicated at 64 for focussing an image on the photoconductive surface ofthe film 44. A corona wire 66 is disposed quite close to the surface ofthe coating 48 but out of focus with respect to the optical system 64,said wire 66 being connected to a source of high voltage shown at 68.Spaced above the position of the member 42 during exposure is themounting (not shown) for the removable capsule 10. When in place, asshown, there is a pressure pad 70 of rigid material such as metal orsome resin just to the rear of the capsule l0, considering the wall 12as its front. The pressure pad 70 could be just touching the rear wall28 if desired. An eccentric cam 72 engages the rear surface of thepressure pad and is mounted for rotation with a shaft 74 that is drivenby a motor '76. The motor '76 is adapted to be energized from anelectric power source 78 which could be used for other functions in theapparatus 62. The motor rotation is controlled by a timer 80 and startedby a switch 82 whose operating lever 84 is in the path of movement ofthe carrier 60 as it rises. The contact extension 4ll is in engagmentwith a wiper 86 connected by the lead 22 to the dc voltage source 78.

The operation of the apparatus 62 is as follows: The image from theoptical system 64 is focussed on the sur face 48 either during chargingby the wire 66 or directly thereafter. When a potential of charge whichis measured by a suitable instrument has been reached, the light imageis cut off by means of a blinder member 88 which blocks off the opticalsystem 64 and leaves the film 44 in darkness. Immediatley thereafter thecarrier 60 rises the brings the member 42 into engagment with the frontsurface of the capsule 10. When perfect alignment of the perforated area34 and the film 44 has been achieved, the right-hand side of the carrier60 moves the lever 84 to close the switch 82. The motor 76 rotates onerevolution very quickly, say in one second or less. During this time thecam 72 pushes the pressure pad 70 in and then releases the same. Thelateral walls 28 of the capsule collapse (FIG. 5) squeezing tonersuspension into the chamber 54 and upon release by the pad 70, the wallsrecover due to the resilience ofinternal spongelike mass 26. This latteraction serves to suck the remaining toner suspension back into theinterior of the capsule 10 (FIG. 6).

FIGS. 4, 5 and 6 show the sequence of events which occur for eachrevolution of the cam 72. In FIG. 4 the capsule It) and the member 42are in place, but nothing has happened. The chamber 54 is empty, thesponelike mass 36 is saturated with the suspension of toner particles intoner liquid, the latent image has been produced on or in the surface ofthe layer 48, the extension 4ll is connected to a source of biasvoltagev In FIG. 5 the cam 72 has rotated half way and squeezed thepressure pad 70 against the rear skin or wall 28 of the capsule It). Nowthe side walls have collapsed as shown at 28 in FIG. 5 and the tonersuspension has been expelled into the chamber 54 substantially fillingthe same. The suspension is shown at 90 in FIG. 5. The action in thechamber 54 will be explained in detail in connection with FIG. 1 below.

Toner particles now adhere to the surface of the film 44 to render thelatent image visible. The cam "72 continues to rotate and the resilienceof the spongelike mass 26 causes the walls 28 to recover to thecondition shown in FIG. 6. In the process of such recovery, the liquidin the chamber 54 is sucked back into the interior of the capsule 10through the perforations 14, leaving very little of the suspension inthe chamber 54. The spacing between surface 34 and the photoconductivesurface 48 is practically capillary in nature and hence the chamber 54will be quite dry. Additionally the orientation of the chamber 54 has noadverse effect on the operation. The moisture that does remain willevaporate quickly when the film 44 is exposed to air. The tonerparticles which adhere are shown at 92 clumped on the surface of thephotoconductive coating 48 in accordance with the latent image chargeformed thereon.

Thereafter, the film member 42 may be removed and examined and thecapsule 10 removed and discarded.

Apparatus for fusing the toner will conveniently be provided in theapparatus 62. For another exposure of the same film member 43 ordifferent one, the carrier 60 is lowered to its original position. Foradditional toning the capsule 10 may be replaced by a fresh one orreused another time or two if toner remains.

The apparatus 62 may be varied by having the capsule 10 move to aposition in juxtaposition to the film 44 wihtout moving the film, inwhich case the blinder member 88 may be eliminated and means must beprovided to prevent the corona wire 66 from interfering with movement ofthe capsule 10.

The operation of the apparatus as explained above takes into accountwhat happens during the processing of the film 44. This is probably bestexplained in connection with FIG. 1.

In FIG. 1 it is assumed that the capsule 10 is being squeezed and thespongelike mass is being compressed. The toner suspension absorbed inthe capillaries of the mass 26 comprises minute particles of carbon,resin and the like, either black or colored, in a liquid which has anelectrophoretic relationship with the particles. This means that in thesuspension, the movement of the particles has caused them to assume asurface charge which they retain when they are expressed from thespongelike mass. In most cases these charges are posi tive charges, andin order to indicate this, stream of liquid suspension 90 are shownemerging from the perforations 14 carrying irregular shaped particles 92with positive charges.

The surface 18 of the foraminous member 12 is coated with a very thinlayer of metal such as aluminum. This layter is very thin, as would beconcluded from an understanding that hte thickness of the wall 12illustrated in FIG. 1 itself is only on millimeter or so. The depositcan be made by vacuum depositing techniques, and is made prior toperforating the wall so that the perforations 14 pass fully and cleanlythrough the layer 20.

The particles 92 are forced through the passageways represented by theperforations 14 at great speed and directed normal to the surface of'tephotoconductive layer 48. Since these particles are already chargedpositively, they will seek out and be attracted to the negativelycharged electrons constituting the latent image in the surface of thecoating 48. As mentioned, the field represented by these electrons whichof course are negatively charged, is weak away from the surface of thecoating 48. This causes the edge effect in prior systems ofelectrostatic processing. The high pressure nozzle effect of theperforations which is illustrated in the chamber 54in FIG. 1 obviatessome of this but in addition, the praticles are electrostatically drivendirectly to the phtoconducitve surface. The layer 20 is kept at apositive potential of about 50 volts dc. to provide a bias effect. Theeffect is not felt while the particle 92 are passing through theperforations 14 because of their force and speed, but does become animportant factor when they leave the openings. Since th particles arepositively charged and the layer 20 is also positive, the particles 92are repelled strongly and driven away from the layer and toward thesurface of the coating 48. They adhere at the surface to form thevisible image, as shown in FIG. 6.

It is to be understood that if the particles require it, they could becharged negatively. Thus, the photoconductive layer 48 might be a p-typelayer, with holes produced on its surface by the corona wire instead ofelectrons. Then the negatively charged particles would adhere to theholes. The image would be reverse. The bias of layer 20 would then beconnected to a negative source of do potential.

Variations in the structure illustrated and described will occur tothose skilled in this art. The embodiments herein are only exemplary,the scope of the invention being defined in the claims attached hereto.

What it is desired to secure by Letters Patent of the United States is:

1. Apparatus for applying toner particles to an electrophotographicmember whose photoconductive surface has a latent image thereon whichcomprises:

A. means for supporting said electrophotographic member with thephotoconductive surface thereof arranged to receive liquid thereon,

B. a source comprising a container of toner particles suspended in aliquid which has an electrophoretic relationship with said particles,said container comprising collapsible but recoverable side walls and aforaminous rigid insulative top wall having a conductive coating on theexterior surface thereof, said exterior surface and conductive coatingbeing of a configuration which is similar to the configuration of saidphotoconductive surface and being arranged parallel to and spaced fromsaid phtoconductive surface, the foramina of said insulative top wallextending through said coating,

C. a source of electric potential connected to said conductive coatingto bias the said conductive coating with respect to said photoconductivesurface.

D. means on the exterior of the container capable of exerting force onthe container to drive the toner suspension from the interior of saidcontainer through said foraminous top wall and conductive coating andagainst said photoconductive surface substantially simultaneously overthe entire area of said surface to apply toner thereto by at leasttemporarily collapsing said side walls to reduce the interior volume ofthe container while a bias voltage is being applied to said conductivecoating from said source of electric.

E. means for withdrawing into said container any excess suspension whichremains, if any, after said toner has been so applied to saidphotoconductive surface, and

F. means on one of the electrophotographic member support and said topwall for confining the spread of suspension to the photoconductivesurface of said electrophotographic member during application of saidtoner thereto and until withdrawal of any excess toner has beencompleted.

2. Apparatus as claimed in claim 1 in which said lastmentioned meanscomprise a frame formed on the electrophotogrphic member support, saidframe defining a recess confining the suspension.

3. Apparatus as claimed in claim 1 in which the remaining walls of thecontainer are imperforate and means are provided inside said containerfor storing said toner suspension.

4. Apparatus as claimed in claim 1 and resilient means inside thecontainer capable of being compressed during collapse of said side wallsand recoverable with recovery of said side walls thereby functioning assaid means for withdrawing excess suspension.

5. Apparatus as claimed in claim 4 in which said means exerting force onthe container comprises an external pressure member operable in a cycleduring which said pressure member moves against at least one ofthe wallsof the container and then moves oppositely.

6. Apparatus as claimed in claim 4 in which the resilient means arecapillary in nature and occupy substantially the full interior volume ofthe container.

7. Apparatus as climed in claim 6, in which said resilient meanscomprise a spongelike mass.

8. A capsule for use in applying toner to the latent image formed on thephotoconductive surface of an electrophotographic film in electrostaticimage recording apparatus which comprises:

A. enclosure means having a supply of toner therein suspended in aliquid havng an eletrophoretic relationship with the toner particles,

B. said enclosure means comprising a container having a floor, flexiblecollapsible yet recoverable side walls and an insulative, substantiallyrigid top wall member, said top wall member having a framinous areaspaced inwardly of the periphery thereof to define a border, saidforaminous area adapted to be arranged parallel with and spaced from thesaid photoconductive surface when dispensing is effected,

C. said side walls capable of being temporarily collapsed by externalpressing to decrease the interior volume of said enclosure means andthereby to expel toner suspension from the foramina of said rigid topwall member simultaneously over said foraminous area while spaced fromsaid photoconductive surface.

9. The capsule as claimed in claim 8 in which there is a spongelikeresilient mass within the container holding said suspension and beingcompressible with the collapse of said side walls to express saidsuspension and recoverable with recovery of said side walls to effectreturn passage of toner suspension through said foramina duringrecovery.

10. The capsule as claimed in claim 9 in which a liquid impervious coversheet removably is engaged over said foraminous area to preserve saidsuspension prior to use thereof.

11. The capsule as claimed in claim 10 in which the removable coversheet is a sticker having a pressuresensitive adhesive carrying surface,and said surface is engaged with said top wall member.

12. The capsule as claimed in claim 9 in which said top wall is flat andsaid container has a peripheral flange congruent with said top wallmember, and the said flange and said border being in sealed engagement.

13. The capsule as claimed in claim 12 in which the container is formedof insulating material and said top wall member has an outer coating ofconductive material for connection to an external electric potentialsource.

M. The capsule as claimed in claim 9 in which said top wall member hasan outer coating of conductive material adapted to be connected to anelectric poten- UNITED STATES PATENT semen @ERNMCATE F QQRREQTEQN PATENTNO. 3,878,817

DATED April 22, 1975 mvemoerm MANFRED R, KUEHNLE it is certified thaterror appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below: Column 1, line 54, change"rapdidly" to -rapidly- =1; column 1, line 55, change "particels" to--particles-; column 1, line 62, change "acheive" to =-=achieve--;column 3, line 9,change losses" to --loses--; column 3, line 63, change"teh" to --=-the-; column 3, line 65, change "too" to --to-; column 5,line 16, change "applicaiton" to --=-application-; column 5, line 23,change "susupension" to suspension-= column 5, line 28, change The" tothe--; column 5, line 43, change "Juxtaposition" to --juxtapositioncolumn 5, line 48, delete "of the invention (second occurrence); column5, line 52, change "thorugh" to -through--,- column 5, line 66, change"turnpentinelike" to -=-turpentinelike--; column 6, line 43 change 388"to --38--; column 7, line 3, change "illusu'trated" to--illustratedcolumn 7, line 10, change "theh" to -=the--; column 7, line12, change "phtocondcutive" to --photoconductive--- column 8, line 18,change "Immediatley" to Immediately-; column 8, line 36, change"sponelike" to -spongelikecolumn 9, line 34, change "hte to --the-;column 9, line 53 change "praticles" to -particles-; column 9, line 5%,change phtoconducitve" to -=-=photoconductive--; column .9, line 59,change "th" to -=the=-=-=; column 10, line 27, change "phtocon-" to-photocon--; column 10, line 44 change "electric," to --=-electricpotential,--; column 10, line 57, change "electrophotogrphic" to=-electrophotographic--; and column ll, line 9, change "climed" to==--claimed--.

and eale this sixteenth ay 0? September 1975 [semi RUTH C. MASDNArresting Officer C, MARSHALL DANN Commissioner uj'PaIenIs andTrademarks

1. Apparatus for applying toner particles to an electrophotographicmember whose photoconductive surface has a latent image thereon whichcomprises: A. means for supporting said electrophotographic member withthe photoconductive surface thereof arranged to receive liquid thereon,B. a source comprising a container of toner particles suspended in aliquid which has an electrophoretic relationship with said particles,said container comprising collapsible but recoverable side walls and aforaminous rigid insulative top wall having a conductive coating on theexterior surface thereof, said exterior surface and conductive coatingbeing of a configuration which is similar to the configuration of saidphotoconductive surface and being arranged parallel to and spaced fromsaid phtoconductive surface, the foramina of said insulative top wallextending through said coating, C. a source of electric potentialconnected to said conductive coating to bias the said conductive coatingwith respect to said photoconductive surface, D. means on the exteriorof the container capable of exerting force on the container to drive thetoner suspension from the interior of said container through saidforaminous top wall and conductive coating and against saidphotoconductive surface substantially simultaneously over the entirearea of said surface to apply toner thereto by at least temporarilycollapsing said side walls to reduce the interior volume of thecontainer while a bias voltage is being applied to said conductivecoating from said source of electric. E. means for withdrawing into saidcontainer any excess suspension which remains, if any, after said tonerhas been so applied to said photoconductive surface, and F. means on oneof the electrophotographic member support and said top wall forconfining the spread of suspension to the photoconductive surface ofsaid electrophotographic member during application of said toner theretoand until withdrawal of any excess toner has bEen completed. 1.Apparatus for applying toner particles to an electrophotographic memberwhose photoconductive surface has a latent image thereon whichcomprises: A. means for supporting said electrophotographic member withthe photoconductive surface thereof arranged to receive liquid thereon,B. a source comprising a container of toner particles suspended in aliquid which has an electrophoretic relationship with said particles,said container comprising collapsible but recoverable side walls and aforaminous rigid insulative top wall having a conductive coating on theexterior surface thereof, said exterior surface and conductive coatingbeing of a configuration which is similar to the configuration of saidphotoconductive surface and being arranged parallel to and spaced fromsaid phtoconductive surface, the foramina of said insulative top wallextending through said coating, C. a source of electric potentialconnected to said conductive coating to bias the said conductive coatingwith respect to said photoconductive surface, D. means on the exteriorof the container capable of exerting force on the container to drive thetoner suspension from the interior of said container through saidforaminous top wall and conductive coating and against saidphotoconductive surface substantially simultaneously over the entirearea of said surface to apply toner thereto by at least temporarilycollapsing said side walls to reduce the interior volume of thecontainer while a bias voltage is being applied to said conductivecoating from said source of electric. E. means for withdrawing into saidcontainer any excess suspension which remains, if any, after said tonerhas been so applied to said photoconductive surface, and F. means on oneof the electrophotographic member support and said top wall forconfining the spread of suspension to the photoconductive surface ofsaid electrophotographic member during application of said toner theretoand until withdrawal of any excess toner has bEen completed. 2.Apparatus as claimed in claim 1 in which said last-mentioned meanscomprise a frame formed on the electrophotogrphic member support, saidframe defining a recess confining the suspension.
 3. Apparatus asclaimed in claim 1 in which the remaining walls of the container areimperforate and means are provided inside said container for storingsaid toner suspension.
 4. Apparatus as claimed in claim 1 and resilientmeans inside the container capable of being compressed during collapseof said side walls and recoverable with recovery of said side wallsthereby functioning as said means for withdrawing excess suspension. 5.Apparatus as claimed in claim 4 in which said means exerting force onthe container comprises an external pressure member operable in a cycleduring which said pressure member moves against at least one of thewalls of the container and then moves oppositely.
 6. Apparatus asclaimed in claim 4 in which the resilient means are capillary in natureand occupy substantially the full interior volume of the container. 7.Apparatus as climed in claim 6, in which said resilient means comprise aspongelike mass.
 8. A capsule for use in applying toner to the latentimage formed on the photoconductive surface of an electrophotographicfilm in electrostatic image recording apparatus which comprises: A.enclosure means having a supply of toner therein suspended in a liquidhavng an eletrophoretic relationship with the toner particles, B. saidenclosure means comprising a container having a floor, flexiblecollapsible yet recoverable side walls and an insulative, substantiallyrigid top wall member, said top wall member having a foraminous areaspaced inwardly of the periphery thereof to define a border, saidforaminous area adapted to be arranged parallel with and spaced from thesaid photoconductive surface when dispensing is effected, C. said sidewalls capable of being temporarily collapsed by external pressing todecrease the interior volume of said enclosure means and thereby toexpel toner suspension from the foramina of said rigid top wall membersimultaneously over said foraminous area while spaced from saidphotoconductive surface.
 9. The capsule as claimed in claim 8 in whichthere is a spongelike resilient mass within the container holding saidsuspension and being compressible with the collapse of said side wallsto express said suspension and recoverable with recovery of said sidewalls to effect return passage of toner suspension through said foraminaduring recovery.
 10. The capsule as claimed in claim 9 in which a liquidimpervious cover sheet removably is engaged over said foraminous area topreserve said suspension prior to use thereof.
 11. The capsule asclaimed in claim 10 in which the removable cover sheet is a stickerhaving a pressure-sensitive adhesive carrying surface, and said surfaceis engaged with said top wall member.
 12. The capsule as claimed inclaim 9 in which said top wall is flat and said container has aperipheral flange congruent with said top wall member, and the saidflange and said border being in sealed engagement.
 13. The capsule asclaimed in claim 12 in which the container is formed of insulatingmaterial and said top wall member has an outer coating of conductivematerial for connection to an external electric potential source.